I am using we-retail in AEM 6.3 and integrated with AA and AAM via DTM. In DTM, i have defined an eVar11 to capture "Cart Count" based on .CSS. Now the question is in AAM while defining the trait, should in trait builder use "c_evar11" or "evar11"?
When setting up the trait expressions in Audience Manager for evars, please use "c_evar".
In your example, eVar11 to capture "Cart Count" would be (c_evar11 == "value") in Audience Manager.